Method of stiffening loops of a fabric and product



United States Patent C) 3,547,750 METHOD OF STIFFENING LOOPS OF A FABRICAND PRODUQT Jean Bussac, Regny, France, assignor to AnciensEtablissements .lalla, Paris, France, a body corporate No Drawing. FiledMar. 8, 1967, Ser. No. 621,428 Claims priority, application France, Mar.17, 1966, 53,865; Dec. 20, 1966, 88,128 Int. Cl. D0311 27/08 US. Cl.161-66 Claims ABSTRACT OF THE DISCLOSURE A new kind of pile fabric inwhich the small loops or so-called terry loops are stiffened by havingdeposited thereon an emulsifiable thermoplastic resin containing asubstantial amount of triazine and a soluble salt of a metal of Group IIof the Periodic Table of elements, the stiffened loops permitting theutilization of the fabric for a number of purposes in which high rubbingfriction is required. The invention also includes a method of stiffeningthe loops.

The present invention is directed to a novel looped pile fabric which ischaracterized in that the loops are stiffened over at least part of thesurface of the fabric. The invention is also directed to the differentarticles which can be manufactured with the novel fabric, especiallyarticles used for rubbing purposes, such as towels, face cloths andgloves, dish-cloths and floor-cloths, carpets, conveyor-belts or othersimilar articles which can be employed to exert friction or withstandrepeated rubbing during use. The invention also comprises a method forthe manufacture of fabrics and articles having stiffened terry loops.

Terry loop fabrics are well known and are suited to a number ofdifferent uses; generally speaking, soft and supple terry loops are notintended either to withstand more or less energetic rubbing or to exertfriction. The present invention provides an unexpected and highly usefultechnical improvement as a result of the creation of a new kind oflooped pile fabric in which the terry loops have a degree of hardnesswhich permits the utilization of the fabric for a number of differentpurposes in which more or less high rubbing friction is required.

The invention has the additional advantage of per mitting the ready andeconomic conversion of a looped fabric of known type to a fabric havingstiffened loops. The method according to the invention makes thisconversion possible both on the fabric itself and on articles which havealready been made such as, for example, bath towels, face-cloths,gloves, rugs and carpets, and so forth; the method can also be appliedto the entire surface of the fabric or article, or alternatively to onlyone portion or selected portions of this surface. Thus, the novel fabriccan have stiffened loops on only one face or on both faces.

The fabric and the articles in accordance with the invention can beobtained from all conventional looped fabrics whether woven or knitted,for example the fabrics commonly known as Turkish towelling, andparticularly textile materials formed of cellulose fibres or containingsuch fibres. Among other fabrics which are suitable for this purpose,mention can be made of those 3,547,750 Patented Dec. 15, 1970 which areformed of mixed textile yarns, such as cellulose yarns (cotton, linen)and animal yarns (wool, silk) and/or cellulose and synthetic yarns(nylon and the like).

By way of example, the articles in accordance with the invention can bebath towels, one face of which is untreated and therefore soft andabsorbent whereas, on the other face, all or part of the terry loops arestiffened, which makes it possible to utilize this face of the towel forrubbing purposes. Another example consists in the treatment offace-cloths of the glove type, in which only the outer face is providedwith hardened terry loops, with the result that the users hand is incontact with the soft internal face of the glove fabric; consequently,gloves of this type are very pleasant both to wear and to handle. Oneapplication which illustrates the stiffening of loops on both faces ofthe fabric is the manufacture of rugs and carpets, in particular matsfor dogs.

The method according to the invention consists in depositing on theloops to be stiffened an aqueous suspension of an emulsifiablethermoplastic resin containing triazine and a soluble salt of a metal ofGroup II of the Periodic Table of elements, and in drying the loops thustreated.

Preferably, the suspension utilized also contains a finishing resin ofknown type.

By way of emulsifiable thermoplastic resins, mention can be made of theacrylic, methacrylic and/or vinyl resins which are particularlysuitable. Thus, successful use can be made of commercially availableaqueous emulsions of polyacrylates of methyl, ethyl, butyl etc., of thecorresponding polymethacrylates, of acrylomethacrylic copolymers suchas, for example, a copolymer of ethyl and of methyl methacrylate;polymers of this type are found in commerce under trade names such asPerapret F, Ucecryl PO, and others.

Excellent results are also obtained with aqueous emulsions of polymersor copolymers such as polyvinyl acetate, or alternatively polyvinylformate, propionate or chloride; also suitable for the purpose are theemulsions 0f the copolymer of polyvinyl chloride and polyvinyl acetate.Suitable vinyl resins are marketed under the trade-marks Rhodoplas,Afcolac, Mowilith, etc.

The salt of a metal of Group II of the Periodic Table of elements whichserves as catalyst can be, for example, a chloride, sulphate, nitrate,perchlorate, chloroacetate etc. of zinc, beryllium, magnesium, calciumor any other alkaline-earth metal.

As regards triazine, it is possible to employ the technical product ofthe type which is marketed under the trademark Stabitex D 46 and whichcontains approximately 50% triazine.

As concerns the finishing resin, which is a highly desirable additionagent in the suspension, such a resin is advantageously selected fromthe polyethers of ethylene-glycol or polyoxy-ethylene compounds, andparticularly useful is a diester of a condensation product offormaldehyde with ethylene glycol; thus, diglycol-formal diacetate isespecially suitable.

It may prove useful also to add to the suspension a known thickeningagent such as, for example, the watersoluble condensation productobtained by the reaction of urea and formaldehyde, a polyvinyl alcoholor the like.

Although the composition of the suspension can vary over a fairly widerange depending on the required degree of stiffening of the loops, thenature of the resin and of the fabric to be treated, and also dependingon other conditions, the proportions of constituents indicated above areusually of the order of:

G. Emulsifiable thermoplastic resin 10 to 150 Triazine 2 to 80*Finishing resin 2 to 25 Thickening agent to 10 Metal salt 2 to 20 asexpressed in dry substance per liter of suspension. Preferably, theproportion of thermoplastic resin is approximately 40 to 55% of thetotal constituents except water.

The foregoing indications are not given in any limiting sense.

The aqueous suspension can be applied on the looped fabric by any knownmeans such as coating, spraying or impregnation. The spray atomizationsystem is of particular interest and highly convenient in practice,especially in the form of either one or a number of feed-racks which areemployed for the purpose of spraying very small droplets of thesuspension onto the fabric. The operation is usually performed on loopedpile fabric which has undergone bleaching followed by drying afterdelivery from the loop.

The quantity of suspension to be employed per square meter of fabricvaries according to the nature of the fabric, the composition of thesuspension and the degree of stiffening which is sought. As a rule, thequantity is of the order of 50 ml. to 800 ml. per square meter ofsurface but, in the majority of cases, varies between 100 and 300 ml.

After the desired quantity of suspension has been applied to the loops,the fabric is subjected to a drying process which can take place at anytemperature which is compatible with the heat resistance of the textilebeing processed and the constituents employed; the drying process can beperformed, for example, between room temperature and 200 C., but rapiddrying without causing damage to the material is obtained preferablybetween 100 and 15 0 C. In the vicinity of 15 0 C., only a few minutesare required for the loop fabric to be ready for use.

The examples which now follow are intended to provide explanatoryillustrations of the invention, but are not given in any sense by way oflimitation.

EXAMPLE 1 With a view to converting terry-cloth bath towels (of Turkishtowelling material) to rubbing-down towels, 1 liter of aqueoussuspension was sprayed onto 5 square meters of this fabric, that is tosay onto towels, and was prepared as follows:

30 g. of emulsion containing 50% polyvinyl acetate known by thetrademark iRhodopas were admixed with 7 g. of commercially availablediglycol-formal diacetate known by the trademark Knittex POM 60, with 10g. of 50% triazine (trademark: Stabitex D 46), 5 g. of a thickeningagent having a urea-formaldehyde base (known as Texapret S) and 5 g. of90% magnesium chloride.

The quantity of water added to this mixture was such that the finalvolume was 1,000 ml.

The suspension obtained therefore contained the following proportionsper liter as expressed in dry substance:

G. Polyvinyl acetate Diglycol-formal diacetate 3.5 Triazine 5Urea-formaldehyde 2.8 Magnesium chloride 4.5

After this suspension had been applied on the towels, the latter werethen dried by passing through an oven for a period of 3 minutes at 140C. After cooling by air blast on delivery from the oven, the towels wereready for use as rubbing-down towels, the terry loops having beenperfectly stiffened.

4 EXAMPLE 2 An aqueous suspension was sprayed on a thick cottonterry-cloth fabric in a proportion of 0.1 liter per square meter; thesuspension contained per liter:

g. of copolymer of ethyl acrylate and methyl methacrylate,

70 g. of triazine,

20 g. of zinc nitrate,

these materials being measured in the dry state.

The treated fabric was dried in an air stream at approximately l10130 C.

There was thus obtained an article with well-stiffened loops andaffording high resistance to friction, which was particularly wellsuited for either wet or dry cleaning of floors and the like surfaces.

EXAMPLE 3 A suspension which was similar to the one described in Example1 Was prepared with 17.5 g. of polyvinyl acetate instead of 15 g. It wasemployed for the purpose of coating looped pile carpets on both sidesand in a proportion of 0.25 liter per square meter. Drying was effectedat 150 C. in approximately three minutes.

The hardened-loop carpets thus obtained had high resistance to wear.

EXAMPLE 4 Carpets such as those of Example 3 were manufactured in thesame manner and using a similar suspension in which polyvinyl acetatewas replaced by 23 g. of methyl polyacrylate.

EXAMPLES 5 to 8 Number of Example N0. Products omitted washings Triazine10 6- Magnesium chloride. 10 7. Diglycol-iormal diacetate 14 8.Urea-formaldehyde 150 1 None 300 Thus, when triazine and magnesiumchloride are not present, there is no stiffening of loops which aretreated with polyvinyl acetate; these two adjuvants produce a certaindegree of stiifening, even if the finishing resin (diglycol-formaldiacetate) is not present, as is shown in Example 7, but the resistanceto washings is in that case fairly low (14). Example 8 shows that theomission of thickening agent reduces resistance to washings to a smallextent compared with Example 1. In the final analysis, it can be seenthat triazine and the magnesium salt are essential and that thefinishing resin is very important in order to obtain loops ofsufficiently permanent stiffness.

What is claimed is:

1. A pile fabric having stiffened loops, which contains in the drystate, per square meter, 0.5 to grams of a thermoplastic materialselected from the group consisting of polyvinyl acetate, polyvinylformate, polyvinyl propionate, polyvinyl chloride, copolymer of vinylchloride with vinyl acetate, lower alkyl polyacrylate, lower alkylmethacrylate and copolymer of ethyl acrylate with methyl methacrylate,and 0.1 to 64 grams of triazine.

2. A fabric according to claim 1, which contains in the dry state, persquare meter, 1 to 45 grams of polyvinyl acetate, and 0.2 to 24 grams oftriazine.

3. A fabric according to claim 1, which contains in the dry state, persquare meter, 1 to 45 grams of ethyl acrylate and methyl methacrylatecopolymer and 0.2 to 24 grams of triazine.

4. A method of stiffening loops of a fabric, which consists indepositing on the loops an aqueous suspension of a thermoplasticmaterial selected from the group consisting of polyvinyl acetate,polyvinyl formate, polyvinyl propionate, polyvinyl chloride, copolymerof vinylchloride and vinyl acetate, lower alkyl polyacrylate, loweralkyl polymethacrylate and copolymer of ethyl acrylate with methylmethacrylate, containing triazine and a salt selected from the groupconsisting of zinc, beryllium, magnesium and calcium as metal componentand chlorides, sulfates, nitrates, perchlorates and chloroacetates, asanion component; said suspension containing per liter 10 to 150 grams ofthe thermoplastic material, 2 to 80 grams of triazine and 2 to 20 gramsof the salt; and then drying the fabric at a temperature which does notexceed 200 C.

5. The method according to claim 4, wherein said suspension contains perliter 2 to 25 grams of a finishing resin selected from the groupconsisting of polyethers of ethylene-glycol, polyoxyethylenes anddiesters of a condensation product of formaldehyde with ethylene-glycol.

6. The method according to claim 5, wherein the drying temperatureranges from 100 C. to 150 C.

7. The method according to claim 4, which consists in spraying onto theloops an aqueous suspension containing, per liter, 10 to 150 grams ofpolyvinyl-acetate, 2 to 80 grams of triazine, 2 to 20 grams of a saltselected from the group consisting of magnesium chloride, magnesiumnitrate, zinc chloride and zinc nitrate, 2 to 25 grams ofdiglycol-formal diacetate and to grams of water solubleurea-formaldehyde resin, the weight of polyvinyl acetate constitutingabout 40 to 55% of the total weight of the components of the suspensionother than water, while the weight ratio of the polyvinyl acetatecontent to the triazine content is between 1.5 and 5, and in then dryingthe fabric at a temperature of 100 to 140 C.

8. The method according to claim 4, which consists in spraying onto theloops an aqueous suspension containing, per liter, 10 to 150 grams ofethyl polyacrylate, 2 to 80 grams of triazine, 2 to grams of a saltselected from the group consisting of magnesium chloride, magnesiumnitrate, zinc chloride and zinc nitrate, 2 to grams of diglycol-formaldiacetate and 0 to 10 grams of water soluble urea-formaldehyde resin,the weight of ethyl polyacrylate constituting about 40 to 55% of thetotal 6 weight of the components of the suspension other than water,while the weight ratio of the ethyl polyacrylate content to the triazinecontent is between 1.5 and 5, and in then drying the fabric at atemperature of 100 to 140 C.

9. The method according to claim 4, which consists in sprayin onto theloops an aqueous suspension containing, per liter, 10 to 150 grams ofmethyl polymethacrylate, 2 to 80 grams of triazine, 2 to 20 grams of asalt selected from the group consisting of magnesium chloride, magnesiumnitrate, zince chloride and zinc nitrate, 2 to 25 grams ofdiglycol-formal diacetate and 0 to 10 grams of water solubleurea-formaldehyde resin, the weight of methyl polymethacrylateconstituting about 40 to of the total weight of the components of thesuspension other than water, while the weight ratio of the methylpolymethacrylate content to the triazine content is between 1.5 and 5,and in then drying the fabric at a temperature of 100 to 140 C.

10. The method according to claim 4, which consists in spraying onto theloops an aqueous suspension containing, per liter, 10 to 150 grams ofethyl acrylate and methyl methacrylate copolymer, 2 to grams oftriazine, 2 to 20 grams of a salt selected from the group consisting ofmagnesium chloride, .magnesium nitrate, zinc chloride and zinc nitrate,2 to 25 grams of diglycol-formal diacetate and 0 to 10 grams of watersoluble urea-formaldehyde resin, the weight of ethyl acrylate and methylmethacrylate copolymer constituting about 40 to 55% of the total weightof the components of the suspension other than water, while the weightratio of the ethyl acrylate and methyl methacrylate copolymer content tothe triazine content is between 1.5 and 5, and in then drying the fabricat a temperature of to C.

References Cited UNITED STATES PATENTS 2,590,713 3/1952 Libbey 26-22,609,350 9/1952 Spatt l17161UHE 2,678,924 5/1954 Graulich et a1.26029.6EMN 2,780,562 2/l957 Reinartz et a1. 26029.6EMN 2,940,863 6/1960Bennett et a1. 117l6lUHE WILLIAM J. VAN BALEN, Primary Examiner R. H.CRISS, Assistant Examiner US. Cl. X.R.

